Answer the following questions.
(1) When all the integers from 1 to 2007 are multiplied, how many is 0 lined continuously from ones digit?
(2) When all continuous integers from A to B are multiplied, it is expressed as (A,B) that the number other than 0 appears first in the multiplied number checked sequentially from the ones digit.
For example, since 1 × 2 × 3 × 4 × 5 = 120, (1, 5) = 2.
(2)-1 Find (1, 10).
(2)-2 Find (121,130).
(1) When all the integers from 1 to 2007 are multiplied, how many is 0 lined continuously from ones digit?
(2) When all continuous integers from A to B are multiplied, it is expressed as (A,B) that the number other than 0 appears first in the multiplied number checked sequentially from the ones digit.
For example, since 1 × 2 × 3 × 4 × 5 = 120, (1, 5) = 2.
(2)-1 Find (1, 10).
(2)-2 Find (121,130).
Answer
(1) 500
(2)-1 8
(2)-2 6
(2)-1 8
(2)-2 6
